What is CVE-2026-64266?

CVE-2026-64266 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10, classified as a Use After Free flaw (CWE-416), affecting Linux kernel versions from 2.6.35 onward and patched in 5.10.261, 5.15.212, 6.1.178 and others. CVE-2026-64266 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-64266?

CVE-2026-64266 has a CVSS score of 7.8 out of 10, rated High severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Is there a patch available for CVE-2026-64266?

Yes, CVE-2026-64266 has been patched. Fixed versions include 5.10.261, 5.15.212, 6.1.178 and others. If you are running Linux kernel 2.6.35 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-64266 actively exploited?

CVE-2026-64266 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is Use After Free (CWE-416)?

The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. See MITRE CWE for full details: https://cwe.mitre.org/data/definitions/416.html

CVE-2026-64266

High

In the Linux kernel, the following vulnerability has been resolved: fuse: re-lock request before returning from fuse_ref_folio() fuse_ref_folio() unlocks the request but does not re-lock it before returning. fuse_chan_abort() can end the request and the async end callback (eg fuse_writepage_free()) can free the args while the subsequent copy chain logic after fuse_ref_folio() accesses them, leading to use-after-free issues. Fix this by locking the request in fuse_ref_folio() before returning.

Package Linux Kernel

Published 2026-07-25

Last modified 2026-08-17

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

7.8

out of 10

High

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Vector string

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Weakness type

CWE-416

CVE-2026-64266 is a Use After Free vulnerability

What is Use After Free?

The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. Learn more on MITRE CWE

Affected versions

Linux kernel versions 2.6.35 and later are affected. Fixed in 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.96, 6.18.39, 7.1.4, 7.2 and their respective stable series.

Affected from

≥ 2.6.35

Fixed in

✓ 5.10.261 5.10.x ✓ 5.15.212 5.15.x ✓ 6.1.178 6.1.x ✓ 6.6.145 6.6.x ✓ 6.12.96 6.12.x ✓ 6.18.39 6.18.x ✓ 7.1.4 7.1.x ✓ 7.2

References

8 total

Kernel Git
https://git.kernel.org/stable/c/0e4a5a000123d81234e27a2f8187688cf608f755

Patch
Kernel Git
https://git.kernel.org/stable/c/1ca605cfa59377f0143fb35b5b01360f37d1b7c4

Patch
Kernel Git
https://git.kernel.org/stable/c/1f9156714592356b4fda57beac7eab9c2a462dd3

Patch
Kernel Git
https://git.kernel.org/stable/c/5630da218a45ba80f0aba0846cbe8aa655da122b

Patch
Kernel Git
https://git.kernel.org/stable/c/65a1c2551f7e16085acbb54aedde1feaa559ba7a

Patch

Showing 5 of 8 references View all on NVD

Details

CVE ID CVE-2026-64266

Severity High

CVSS score 7.8 / 10

CVSS version 3.1

Published 2026-07-25

Modified 2026-08-17

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-64266?

CVE-2026-64266 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 , classified as an Use After Free flaw (CWE-416) . It affects Linux kernel versions from 2.6.35 onward and has been patched in 5.10.261, 5.15.212, 6.1.178 and others. CVE-2026-64266 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-64266?

CVE-2026-64266 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
Is there a patch available for CVE-2026-64266?

Yes. CVE-2026-64266 has been patched. Fixed versions include 5.10.261, 5.15.212, 6.1.178 and others. If you are running Linux kernel 2.6.35 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-64266 actively exploited?

No. CVE-2026-64266 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.